Grimsvötn – The Saksunarvatn Tephras

A repost on the past of Grimsvotn, as it seems to be nearing its next eruption, albeit not on the same scale as the one described here! It is sometimes hard to understand the size of the Icelandic volcanic systems. We often read statistical things like “Half of all the ash in Europe” and “One…

Volcanoes of the North: the fire in the ice

A freezer provides storage. And a deep freezer gives deep storage. You can’t go deeper than an original ice-age glacier. In Greenland, those glaciers are still there, being so tall that the top has remained in deep freeze even though the ice age is a distant memory. In this cryogenic environment, that frozen memory is…

Eldgja: Eruption dating

The previous post described what we think we know about the Eldgja eruption. Our knowledge about one of the largest eruptions in Iceland is somewhat limited, surprisingly so given that Iceland was already well populated. One of the few things which seems secure is the date. Eldgja is believed to date to 934 AD, continuing…

Grimsvötn – The Saksunarvatn Tephras

It is sometimes hard to understand the size of the Icelandic volcanic systems. We often read statistical things like “Half of all the ash in Europe” and “One third of all basalt produced in the world” and we still do not really get it because we lack a point of reference. Instead we time after…

1809: The missing volcano

Large eruptions are well known. Mention Pinatubo, Mount St Helens, Krakatoa, Thera, and everyone knows something about it. The Tambora eruption of 1815 is the largest of this set: it caused the “year without summer”, left tell-tale marks in the ice sheets, and remains a terrifying example of the destructive power of volcanoes. But the…

Millennium Volcanoes

As we labour to rescue what can be saved, we shall continue from where we last were. Here again is that fabulous post by Albert, alas, without the original reader comments: Volcanic eruptions have become major attractions, and even rather minor eruptions can make front page news. In modern days, any volcano deciding to erupt…